Sharif Digital Repository

Water-soluble peptidocalix[4]arenes were synthesized by the introduction of arginine-rich narrow groove-binding residues at lower rims through solid-phase synthesis. The study of binding of these water-soluble bidentate ligands to well-matched and mismatched DNA duplexes by fluorescent titrations, ethidium bromide (EB) displacement assays, DNA-melting experiments, and circular dichroism (CD) analysis revealed a sequence-dependent groove-binding mechanism  

In content based image retrieval similarity measurement is one of the most important aspects in a large image database for efficient search and retrieval to find the best answer for a user query. Color and texture are among the more expressive of the visual features. Considerable work has been done in designing efficient descriptors for these features for applications such as similarity retrieval. The MPEG-7 specifies a standard set of descriptors for color, texture and shape. In the Human Vision System (HVS), visual information is not perceived equally; some information may be more important than other information. The purpose of this paper is to show how the MPEG-7 descriptor based on... 

In this paper, a new approach based on a Generalized Regression Neural Network (GRNN) has been proposed to predict the unsteady forces and moments on a 70° swept wing undergoing sinusoidal pitching motion. Extensive wind tunnel results were being used for training the network and for verification of the values predicted by this approach. The Generalized Regression Neural Network (GRNN) has been trained by the aforementioned experimental data and subsequently was used as a prediction tool to determine the unsteady longitudinal forces and moments of the pitching delta wing for various reduced frequencies. The results are in a good agreement with those determined by the previous experimental... 

In this study, ZnO-Red Ochre nanocomposite was green synthesized by Rosa Damascena (RD) extract (RDZRONCs). Proton Induced X-ray Emission microanalysis (Micro-PIXE) and X-ray diffraction (XRD) pattern confirmed the presence of hematite (Fe2O3), and quartz (SiO2) mineral phases in the Red Ochre (RO) nanoclay. In addition, the XRD pattern shows the ZnO, ZnFe2O4, SiO2, Fe2O3, and Si phases in the RDZRONCs that were green synthesized with natural RD extract and RO. The RDZRONCs were used to modify the carbon paste electrode (CPE) for the electrochemical determination of the anticancer drug 5-fluorouracil (5-FU). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques... 

This work suggests a green method for synthesizing Au nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The mechanism of green synthesized AuNPs was examined by molecular electrostatic potential (MEP) calculations. AuNPs were characterized with different techniques such as Ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, X-ray diffraction (XRD), and Transmission electron microscopy (TEM). Electrochemical investigation of modified glassy carbon electrode using AuNPs (AuNPs/GCE) shows that the electronic transmission rate between the modified electrode and [Fe (CN)6]3−/4− increased. Process of oxidation, energy... 

Galbanic acid (GBA), as a natural compound has potential anticancer properties. It has been documented that GBA shows promising therapeutic potential against various types of cancer, including breast, lung, colon, liver, and prostate cancer. Several mechanisms involve im anti-tumor effects of GBA include apoptosis induction, cell cycle arrest, inhibition of angiogenesis, suppression of metastasis, and modulation of immune responses. Furthermore, the synergistic effects of GBA along with chemotherapeutic agents led to has enhancing efficiency with reduction in toxicity. Moreover, GBA through antioxidant and anti-inflammatory properties possess indirect anti-tumor effects. In this review, we... 

Etoposide (EP) is one of the anticancer drugs with wide application and many side effects. Therefore, it is very important to provide a simple, fast and sensitive measurement method to monitor the treatment of patients treated with this drug. In the upcoming research, etoposide has been measured using a carbon paste electrode (CPE) modified with a new green synthesized nanocomposite. To prepare the nanocomposite, first the Lapis lazuli stone was ground by rubbing in a stone mortar. Proton-induced X-ray emission analysis of processed Lapis lazuli showed the presence of specific mineral phases such as SiO2, CaO, Al2O3, MgO, SO3, Na2O, and Fe2O3 that are associated with Lapis lazuli sources.... 

The deployment of multi-agent systems in presence of obstacle deals with autonomous motion of agents toward a specified target by sensing each other and boundaries of obstacles. In this paper, asynchronous, scalable, distributed algorithm is used to deploy agents. Boundaries of obstacles are modeled by virtual agents. Algorithm was implemented by solving continuous n-median problem called generalized Fermat-Weber problem. It is shown that deployment is performed when position of real agents are the geometric median of their Voronoi cells. Simulation results show the validity of the proposed algorithm very well  

One of the security issues in data outsourcing scenario is the enforcement of data owner's access control policies. This includes some challenges; namely, the number of keys required to access authorized resources, efficient policy updating, write access control enforcement, user and data owner overhead, and preserving confidentiality of data and policies. Most of the existing solutions address only some of the challenges, while they impose high overhead on both the data owner and users. Though, policy management in the Role-Based Access Control (RBAC) model is easier and more efficient due to the existence of role hierarchical structure and role inheritance; most of the existing solutions... 

A series of experiments were carried out to study the unsteady wake phenomenon behind an oscillating airfoil. The airfoil is a section of a wind turbine blade oscillating in pitch about the quarter chord axis at various reduced frequencies, oscillation amplitude and mean angles of attack. Streamwise velocity profiles were obtained by real time and instantaneous measurements at 35 vertically aligned points behind the airfoil via two similar rakes. One of rakes has only static pressure probes and the other is equipped with total pressure ones. An estimation of the variation of linear momentum defect during the oscillation is obtained and has been compared with the corresponding static one. The...